From 7c5625227ff8c81953e953d8e25c3eba2ab0aeb3 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 28 Mar 2011 10:29:27 +0800 Subject: [PATCH] KVM: MMU: remove mmu_seq verification on pte update path The mmu_seq verification can be removed since we get the pfn in the protection of mmu_lock. Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/mmu.c | 16 +++++----------- arch/x86/kvm/paging_tmpl.h | 4 +--- 3 files changed, 7 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f7dfd6479d02..ecdc562ea3e2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -274,7 +274,7 @@ struct kvm_mmu { struct kvm_mmu_page *sp); void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva); void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, - u64 *spte, const void *pte, unsigned long mmu_seq); + u64 *spte, const void *pte); hpa_t root_hpa; int root_level; int shadow_root_level; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 22fae7593ee7..28418054b880 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1206,7 +1206,7 @@ static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva) static void nonpaging_update_pte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, u64 *spte, - const void *pte, unsigned long mmu_seq) + const void *pte) { WARN_ON(1); } @@ -3163,9 +3163,8 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu, } static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp, - u64 *spte, - const void *new, unsigned long mmu_seq) + struct kvm_mmu_page *sp, u64 *spte, + const void *new) { if (sp->role.level != PT_PAGE_TABLE_LEVEL) { ++vcpu->kvm->stat.mmu_pde_zapped; @@ -3173,7 +3172,7 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, } ++vcpu->kvm->stat.mmu_pte_updated; - vcpu->arch.mmu.update_pte(vcpu, sp, spte, new, mmu_seq); + vcpu->arch.mmu.update_pte(vcpu, sp, spte, new); } static bool need_remote_flush(u64 old, u64 new) @@ -3229,7 +3228,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_mmu_page *sp; struct hlist_node *node; LIST_HEAD(invalid_list); - unsigned long mmu_seq; u64 entry, gentry, *spte; unsigned pte_size, page_offset, misaligned, quadrant, offset; int level, npte, invlpg_counter, r, flooded = 0; @@ -3271,9 +3269,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, break; } - mmu_seq = vcpu->kvm->mmu_notifier_seq; - smp_rmb(); - spin_lock(&vcpu->kvm->mmu_lock); if (atomic_read(&vcpu->kvm->arch.invlpg_counter) != invlpg_counter) gentry = 0; @@ -3345,8 +3340,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, if (gentry && !((sp->role.word ^ vcpu->arch.mmu.base_role.word) & mask.word)) - mmu_pte_write_new_pte(vcpu, sp, spte, &gentry, - mmu_seq); + mmu_pte_write_new_pte(vcpu, sp, spte, &gentry); if (!remote_flush && need_remote_flush(entry, *spte)) remote_flush = true; ++spte; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index c6397795d865..74f8567d57ac 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -325,7 +325,7 @@ no_present: } static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, - u64 *spte, const void *pte, unsigned long mmu_seq) + u64 *spte, const void *pte) { pt_element_t gpte; unsigned pte_access; @@ -342,8 +342,6 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, kvm_release_pfn_clean(pfn); return; } - if (mmu_notifier_retry(vcpu, mmu_seq)) - return; /* * we call mmu_set_spte() with host_writable = true because that -- 2.20.1